Cannon-pinion for watches



(No Model.)

D. D. PALMER.

cannon PINION FOR WATGHES.

Patnted Jan. 8, 1889.

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n Washington. u C

- UNITED STATES PATENT Orn te.

DOLPHAS D. PALMER, OF YVALTHAM, MASSACHUSETTS.

CANNON-PINION FOR' WATCH ES.

SPEGIIFICA'lION forming part of Letters Patent No. 395,754, datedJanuary 8, 1889.

Application filed June 2, 1888.

To all whom it may concern.-

Be it known that I, DOLPHAS D. PALMER, of altham, county of Middlcsex,State of Massachusetts, have invented an Improvement in Cannon-Pinionsfor Watches, of which the following description, in connection with theaccompanying drawings, is a specification, like letters on the drawingsrepresenting like parts.

This invention has for its object to improve the construction ofcannon-pinions for watches.

In accordance with this invention two or more spring-like arms areformed integral with the pinion which engages a shoulder formed upon thearbor of the center wheel, and a tubular internally-screw-threaded capis placed upon the arbor inclosing the springarmed port-ion of thecannon-pinion, said cap serving as the staff of the cannon.

Figure 1 shows in vertical section a cannonpinion constructed inaccordance with this invention, the center wheel and arbor being shownin elevation; Fig. 2, a side elevation of the cap which forms the staffof the pinion; and Fig. 3, a side elevation of the pinion, the cap orstaff being removed to show the springarms.

The center wheel, (1, having the arbor a, is as usual. The arbor a iscut away, reduced, or tapered, to present an annular shoulder, a Thecannon-pinion Z) and its staff 0 are made of independent pieces. Thepinion b has formed integrz'il with it a screw-threaded hub, 0 and twoor more spring-acting arms, I), which, when the pinion I) is placed uponthe arbor a in proper position, the said springarms I) enter the reducedor tapered portion of the arbor beneath the shoulder The staff 0, whichis made tubular, is internally screw-threaded at one end to engage thescrewthreaded hub D and when said staff is in proper position upon thescrew-threaded hub b the spring acting arms I) are inclosed within saidstait. The staff and pinion are prevented from working off when beingro- $erial No. 275,815. (No model.)

tated (by the halal-setting gear, not shown) by the said shoulder a Oneend of the staff 0 and the opposite end of the pinion 1) act as a guideto hold it in place and. cause it to run true in rotating.

Before tempering the spring-arms 7/ are closed in, which causes them tobind on the arbor a under the shoulder which allows the holes in. thestaff (1 and pinion b to be drilled several degrees larger than thearbor a. The friction of the spring-arms b causes the pinion to movewith the arbor a when the watch is running and allows it to move freelyin setting the hands. The shoulder (1' being beveled allows of thecannon-pinion being removed at will.

.liy this construction the canmini-pinitm will frictionally engage thearbor a, yet may be turned independently of the arbor when desired,andthe pinion b is not slitted, as is now common; also, by this method ofconstruc tion the parts are made entirely interchange able, therebydispensing with the necessity of fitting, as in all other forms known tome each pinion has to be titted to its own arbor. This feature is a veryimportant one, as the fitting of the pinion 'to the arbor costs morethan the manufzui-ture of the pinion.

i. A cannon-pinion for watches, consisting of the pinion I), having thespring-acting arms l1 and the independent tubular staff (3,substantially as described.

2. A cannon-pinion for watches, consisting of the non-slitted pinion I),having the screwthreaded hub Z1 and spring-acting arms 5', and theindependent tubular staff 0, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

'DOLPHAS D. PALMER.

\Yitnesses:

BERNIOE J Novas, F. L. EMERY.

